package com.fanjf.swipebacktemplate.system;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.FrameLayout.LayoutParams;

import java.lang.reflect.Method;

/**
 * Class to manage status and navigation bar tint effects when using KitKat
 * translucent system UI modes.
 * 
 */
@SuppressWarnings( { "rawtypes", "unchecked" } )
public class SystemBarTintManager {

	static {
		// Android allows a system property to override the presence of the
		// navigation bar.
		// Used by the emulator.
		// See
		// https://github.com/android/platform_frameworks_base/blob/master/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java#L1076
		if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT ) {
			try {
				Class c = Class.forName( "android.os.SystemProperties" );
				Method m = c.getDeclaredMethod( "get", String.class );
				m.setAccessible( true );
				sNavBarOverride = (String)m.invoke( null, "qemu.hw.mainkeys" );
			}
			catch( Throwable e ) {
				sNavBarOverride = null;
			}
		}
	}

	/**
	 * The default system bar tint color value.
	 */
	public static final int DEFAULT_TINT_COLOR = 0x99000000;

	private static String sNavBarOverride;

	private final SystemBarConfig mConfig;

	private boolean mStatusBarAvailable;

	private boolean mNavBarAvailable;

	private boolean mStatusBarTintEnabled;

	private boolean mNavBarTintEnabled;

	private View mStatusBarTintView;

	private View mNavBarTintView;

	/**
	 * Constructor. Call this in the host activity onCreate method after its
	 * content view has been set. You should always create new instances when
	 * the host activity is recreated.
	 * 
	 * @param activity The host activity.
	 */
	@SuppressWarnings ("ResourceType")
	@TargetApi( 19 )
	public SystemBarTintManager ( Activity activity) {

		Window win = activity.getWindow();
		ViewGroup decorViewGroup = (ViewGroup)win.getDecorView();

		if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT ) {
			// check theme attrs
			int[] attrs = { android.R.attr.windowTranslucentStatus, android.R.attr.windowTranslucentNavigation };
			TypedArray a = activity.obtainStyledAttributes( attrs );
			try {
				mStatusBarAvailable = a.getBoolean( 0, false );
				mNavBarAvailable = a.getBoolean( 1, false );
			}
			finally {
				a.recycle();
			}

			// check window flags
			WindowManager.LayoutParams winParams = win.getAttributes();
			int bits = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
			if( (winParams.flags & bits) != 0 ) {
				mStatusBarAvailable = true;
			}
			bits = WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION;
			if( (winParams.flags & bits) != 0 ) {
				mNavBarAvailable = true;
			}
		}

		mConfig = new SystemBarConfig( activity, mStatusBarAvailable, mNavBarAvailable );
		// device might not have virtual navigation keys
		if( !mConfig.hasNavigtionBar() ) {
			mNavBarAvailable = false;
		}

		if( mStatusBarAvailable ) {
			setupStatusBarView( activity, decorViewGroup );
		}
		if( mNavBarAvailable ) {
			setupNavBarView( activity, decorViewGroup );
		}

	}

	/**
	 * Enable tinting of the system status bar.
	 * 
	 * If the platform is running Jelly Bean or earlier, or translucent system
	 * UI modes have not been enabled in either the theme or via window flags,
	 * then this method does nothing.
	 * 
	 * @param enabled True to enable tinting, false to disable it (default).
	 */
	public void setStatusBarTintEnabled( boolean enabled ) {
		mStatusBarTintEnabled = enabled;
		if( mStatusBarAvailable ) {
			mStatusBarTintView.setVisibility( enabled ? View.VISIBLE : View.GONE );
		}
	}

	/**
	 * Enable tinting of the system navigation bar.
	 * 
	 * If the platform does not have soft navigation keys, is running Jelly Bean
	 * or earlier, or translucent system UI modes have not been enabled in
	 * either the theme or via window flags, then this method does nothing.
	 * 
	 * @param enabled True to enable tinting, false to disable it (default).
	 */
	public void setNavigationBarTintEnabled( boolean enabled ) {
		mNavBarTintEnabled = enabled;
		if( mNavBarAvailable ) {
			mNavBarTintView.setVisibility( enabled ? View.VISIBLE : View.GONE );
		}
	}

	/**
	 * Apply the specified color tint to all system UI bars.
	 * 
	 * @param color The color of the background tint.
	 */
	public void setTintColor( int color ) {
		setStatusBarTintColor( color );
		setNavigationBarTintColor( color );
	}

	/**
	 * Apply the specified drawable or color resource to all system UI bars.
	 * 
	 * @param res The identifier of the resource.
	 */
	public void setTintResource( int res ) {
		setStatusBarTintResource( res );
		setNavigationBarTintResource( res );
	}

	/**
	 * Apply the specified drawable to all system UI bars.
	 * 
	 * @param drawable The drawable to use as the background, or null to remove
	 *            it.
	 */
	public void setTintDrawable( Drawable drawable ) {
		setStatusBarTintDrawable( drawable );
		setNavigationBarTintDrawable( drawable );
	}

	/**
	 * Apply the specified alpha to all system UI bars.
	 * 
	 * @param alpha The alpha to use
	 */
	public void setTintAlpha( float alpha ) {
		setStatusBarAlpha( alpha );
		setNavigationBarAlpha( alpha );
	}

	/**
	 * Apply the specified color tint to the system status bar.
	 * 
	 * @param color The color of the background tint.
	 */
	public void setStatusBarTintColor( int color ) {
		if( mStatusBarAvailable ) {
			mStatusBarTintView.setBackgroundColor( color );
		}
	}

	/**
	 * Apply the specified drawable or color resource to the system status bar.
	 * 
	 * @param res The identifier of the resource.
	 */
	public void setStatusBarTintResource( int res ) {
		if( mStatusBarAvailable ) {
			mStatusBarTintView.setBackgroundResource( res );
		}
	}

	/**
	 * Apply the specified drawable to the system status bar.
	 * 
	 * @param drawable The drawable to use as the background, or null to remove
	 *            it.
	 */
	@SuppressWarnings( "deprecation" )
	public void setStatusBarTintDrawable( Drawable drawable ) {
		if( mStatusBarAvailable ) {
			mStatusBarTintView.setBackgroundDrawable( drawable );
		}
	}

	/**
	 * Apply the specified alpha to the system status bar.
	 * 
	 * @param alpha The alpha to use
	 */
	@TargetApi( 11 )
	public void setStatusBarAlpha( float alpha ) {
		if( mStatusBarAvailable && Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ) {
			mStatusBarTintView.setAlpha( alpha );
		}
	}

	/**
	 * Apply the specified color tint to the system navigation bar.
	 * 
	 * @param color The color of the background tint.
	 */
	public void setNavigationBarTintColor( int color ) {
		if( mNavBarAvailable ) {
			mNavBarTintView.setBackgroundColor( color );
		}
	}

	/**
	 * Apply the specified drawable or color resource to the system navigation
	 * bar.
	 * 
	 * @param res The identifier of the resource.
	 */
	public void setNavigationBarTintResource( int res ) {
		if( mNavBarAvailable ) {
			mNavBarTintView.setBackgroundResource( res );
		}
	}

	/**
	 * Apply the specified drawable to the system navigation bar.
	 * 
	 * @param drawable The drawable to use as the background, or null to remove
	 *            it.
	 */
	@SuppressWarnings( "deprecation" )
	public void setNavigationBarTintDrawable( Drawable drawable ) {
		if( mNavBarAvailable ) {
			mNavBarTintView.setBackgroundDrawable( drawable );
		}
	}

	/**
	 * Apply the specified alpha to the system navigation bar.
	 * 
	 * @param alpha The alpha to use
	 */
	@TargetApi( 11 )
	public void setNavigationBarAlpha( float alpha ) {
		if( mNavBarAvailable && Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ) {
			mNavBarTintView.setAlpha( alpha );
		}
	}

	/**
	 * Get the system bar configuration.
	 * 
	 * @return The system bar configuration for the current device
	 *         configuration.
	 */
	public SystemBarConfig getConfig() {
		return mConfig;
	}

	/**
	 * Is tinting enabled for the system status bar?
	 * 
	 * @return True if enabled, False otherwise.
	 */
	public boolean isStatusBarTintEnabled() {
		return mStatusBarTintEnabled;
	}

	/**
	 * Is tinting enabled for the system navigation bar?
	 * 
	 * @return True if enabled, False otherwise.
	 */
	public boolean isNavBarTintEnabled() {
		return mNavBarTintEnabled;
	}

	private void setupStatusBarView( Context context, ViewGroup decorViewGroup ) {
		mStatusBarTintView = new View( context );
		LayoutParams params = new LayoutParams( LayoutParams.MATCH_PARENT, mConfig.getStatusBarHeight() );
		params.gravity = Gravity.TOP;
		if( mNavBarAvailable && !mConfig.isNavigationAtBottom() ) {
			params.rightMargin = mConfig.getNavigationBarWidth();
		}
		mStatusBarTintView.setLayoutParams( params );
		mStatusBarTintView.setBackgroundColor( DEFAULT_TINT_COLOR );
		mStatusBarTintView.setVisibility( View.GONE );
		decorViewGroup.addView( mStatusBarTintView );
	}

	@SuppressLint( "RtlHardcoded" )
	private void setupNavBarView( Context context, ViewGroup decorViewGroup ) {
		mNavBarTintView = new View( context );
		LayoutParams params;
		if( mConfig.isNavigationAtBottom() ) {
			params = new LayoutParams( LayoutParams.MATCH_PARENT, mConfig.getNavigationBarHeight() );
			params.gravity = Gravity.BOTTOM;
		}
		else {
			params = new LayoutParams( mConfig.getNavigationBarWidth(), LayoutParams.MATCH_PARENT );
			params.gravity = Gravity.RIGHT;
		}
		mNavBarTintView.setLayoutParams( params );
		mNavBarTintView.setBackgroundColor( DEFAULT_TINT_COLOR );
		mNavBarTintView.setVisibility( View.GONE );
		decorViewGroup.addView( mNavBarTintView );
	}

	/**
	 * Class which describes system bar sizing and other characteristics for the
	 * current device configuration.
	 * 
	 */
	public static class SystemBarConfig {

		private static final String STATUS_BAR_HEIGHT_RES_NAME = "status_bar_height";

		private static final String NAV_BAR_HEIGHT_RES_NAME = "navigation_bar_height";

		private static final String NAV_BAR_HEIGHT_LANDSCAPE_RES_NAME = "navigation_bar_height_landscape";

		private static final String NAV_BAR_WIDTH_RES_NAME = "navigation_bar_width";

		private static final String SHOW_NAV_BAR_RES_NAME = "config_showNavigationBar";

		private final boolean mTranslucentStatusBar;

		private final boolean mTranslucentNavBar;

		private final int mStatusBarHeight;

		private final int mActionBarHeight;

		private final boolean mHasNavigationBar;

		private final int mNavigationBarHeight;

		private final int mNavigationBarWidth;

		private final boolean mInPortrait;

		private final float mSmallestWidthDp;

		private SystemBarConfig(Activity activity, boolean translucentStatusBar, boolean traslucentNavBar) {
			Resources res = activity.getResources();
			mInPortrait = (res.getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT);
			mSmallestWidthDp = getSmallestWidthDp( activity );
			mStatusBarHeight = getInternalDimensionSize( res, STATUS_BAR_HEIGHT_RES_NAME );
			mActionBarHeight = getActionBarHeight( activity );
			mNavigationBarHeight = getNavigationBarHeight( activity );
			mNavigationBarWidth = getNavigationBarWidth( activity );
			mHasNavigationBar = (mNavigationBarHeight > 0);
			mTranslucentStatusBar = translucentStatusBar;
			mTranslucentNavBar = traslucentNavBar;
		}

		@TargetApi( 14 )
		private int getActionBarHeight( Context context ) {
			int result = 0;
			if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH ) {
				TypedValue tv = new TypedValue();
				context.getTheme().resolveAttribute( android.R.attr.actionBarSize, tv, true );
				result = TypedValue.complexToDimensionPixelSize( tv.data, context.getResources().getDisplayMetrics() );
			}
			return result;
		}

		@TargetApi( 14 )
		private int getNavigationBarHeight( Context context ) {
			Resources res = context.getResources();
			int result = 0;
			if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH ) {
				if( hasNavBar( context ) ) {
					String key;
					if( mInPortrait ) {
						key = NAV_BAR_HEIGHT_RES_NAME;
					}
					else {
						key = NAV_BAR_HEIGHT_LANDSCAPE_RES_NAME;
					}
					return getInternalDimensionSize( res, key );
				}
			}
			return result;
		}

		@TargetApi( 14 )
		private int getNavigationBarWidth( Context context ) {
			Resources res = context.getResources();
			int result = 0;
			if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH ) {
				if( hasNavBar( context ) ) {
					return getInternalDimensionSize( res, NAV_BAR_WIDTH_RES_NAME );
				}
			}
			return result;
		}

		@TargetApi( 14 )
		private boolean hasNavBar( Context context ) {
			Resources res = context.getResources();
			int resourceId = res.getIdentifier( SHOW_NAV_BAR_RES_NAME, "bool", "android" );
			if( resourceId != 0 ) {
				boolean hasNav = res.getBoolean( resourceId );
				// check override flag (see static block)
				if( "1".equals( sNavBarOverride ) ) {
					hasNav = false;
				}
				else if( "0".equals( sNavBarOverride ) ) {
					hasNav = true;
				}
				return hasNav;
			}
			else { // fallback
				return !ViewConfiguration.get( context ).hasPermanentMenuKey();
			}
		}

		private int getInternalDimensionSize( Resources res, String key ) {
			int result = 0;
			int resourceId = res.getIdentifier( key, "dimen", "android" );
			if( resourceId > 0 ) {
				result = res.getDimensionPixelSize( resourceId );
			}
			return result;
		}

		@SuppressLint( "NewApi" )
		private float getSmallestWidthDp( Activity activity ) {
			DisplayMetrics metrics = new DisplayMetrics();
			if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN ) {
				activity.getWindowManager().getDefaultDisplay().getRealMetrics( metrics );
			}
			else {
				activity.getWindowManager().getDefaultDisplay().getMetrics( metrics );
			}
			float widthDp = metrics.widthPixels / metrics.density;
			float heightDp = metrics.heightPixels / metrics.density;
			return Math.min( widthDp, heightDp );
		}

		/**
		 * Should a navigation bar appear at the bottom of the screen in the
		 * current device configuration? A navigation bar may appear on the
		 * right side of the screen in certain configurations.
		 * 
		 * @return True if navigation should appear at the bottom of the screen,
		 *         False otherwise.
		 */
		public boolean isNavigationAtBottom() {
			return (mSmallestWidthDp >= 600 || mInPortrait);
		}

		/**
		 * Get the height of the system status bar.
		 * 
		 * @return The height of the status bar (in pixels).
		 */
		public int getStatusBarHeight() {
			return mStatusBarHeight;
		}

		/**
		 * Get the height of the action bar.
		 * 
		 * @return The height of the action bar (in pixels).
		 */
		public int getActionBarHeight() {
			return mActionBarHeight;
		}

		/**
		 * Does this device have a system navigation bar?
		 * 
		 * @return True if this device uses soft key navigation, False
		 *         otherwise.
		 */
		public boolean hasNavigtionBar() {
			return mHasNavigationBar;
		}

		/**
		 * Get the height of the system navigation bar.
		 * 
		 * @return The height of the navigation bar (in pixels). If the device
		 *         does not have soft navigation keys, this will always return
		 *         0.
		 */
		public int getNavigationBarHeight() {
			return mNavigationBarHeight;
		}

		/**
		 * Get the width of the system navigation bar when it is placed
		 * vertically on the screen.
		 * 
		 * @return The width of the navigation bar (in pixels). If the device
		 *         does not have soft navigation keys, this will always return
		 *         0.
		 */
		public int getNavigationBarWidth() {
			return mNavigationBarWidth;
		}

		/**
		 * Get the layout inset for any system UI that appears at the top of the
		 * screen.
		 * 
		 * @param withActionBar True to include the height of the action bar,
		 *            False otherwise.
		 * @return The layout inset (in pixels).
		 */
		public int getPixelInsetTop( boolean withActionBar ) {
			return (mTranslucentStatusBar ? mStatusBarHeight : 0) + (withActionBar ? mActionBarHeight : 0);
		}

		/**
		 * Get the layout inset for any system UI that appears at the bottom of
		 * the screen.
		 * 
		 * @return The layout inset (in pixels).
		 */
		public int getPixelInsetBottom() {
			if( mTranslucentNavBar && isNavigationAtBottom() ) {
				return mNavigationBarHeight;
			}
			else {
				return 0;
			}
		}

		/**
		 * Get the layout inset for any system UI that appears at the right of
		 * the screen.
		 * 
		 * @return The layout inset (in pixels).
		 */
		public int getPixelInsetRight() {
			if( mTranslucentNavBar && !isNavigationAtBottom() ) {
				return mNavigationBarWidth;
			}
			else {
				return 0;
			}
		}

	}

}